Ask HN: How do you build corporate culture?

I have recently become involved with a "task force" at work whose job it is to improve the corporate culture and I wanted to take the opportunity to ask HN what you would define as corporate culture and how a company would go about to create a good culture?

The question in itself is difficult, because it's hard to quantify what good corporate culture means. Is it just about having things like flexible working hours, healthcare, possibility to work remotely, stock programs? Or is it also about hiring the right people, encouraging your employees (how?) or something else?